Children conceived by means of some assisted reproductive technologies run a higher risk of being born with birth defects than do children conceived spontaneously, according to a new study in the journal Fertility and Sterility.

More by Ron Bailey

This has provoked some hand-wringing by University of Pennsylvania bioethicist Arthur Caplan, who observes that the study showed a "large increase" in the risk of having a child with a birth defect compared to the risk of defects in children made "the old-fashioned way"– a 37 percent increase.

"That is a huge number," Caplan asserts. "The large risk factor now on the table needs to be a key part of how everyone thinks about making babies in medical settings."

The researchers looked at the rate of birth defects reported in 46 studies of children born using regular in vitro fertilization (IVF), i.e. producing embryos by exposing eggs in a lab dish to sperm and then transferring them to a womb, as well as intracytoplasmic sperm injection (ICSI), in which a single sperm is injected directly into an egg. The studies, which encompassed the births of just under 125,000 children worldwide, also attempted to determine whether there was any difference in the birth defect rates between regular IVF and ICSI. They did not find much difference in the rate of birth defects between the two techniques.

Prior studies have also found an increase in birth defects among children born by means of assisted reproduction. So what is the magnitude of the risks? I am a bit puzzled about the way that Caplan characterized the results of the new study. What the researchers actually report is an increase in the relative risk of IVF and ICSI birth defects compared to the risk of birth defects among children born through what the fertility gurus label "spontaneous" conception. In the United States the rate of birth defects among children born by spontaneous means is about three out of 100.

What does a 37 percent increase in birth defects among IVF babies represent? Basically, it means that the researchers found that four out of 100 IVF babies are born with birth defects. That is not nothing, but it sure does sound less scary than a 37 percent increase.

How to account for this reported increase in birth defects associated with assisted reproduction? The researchers note that the defects could be due to the underlying infertility of couples seeking treatment. For example, one study found that children born to subfertile couples (often defined as those who took longer than one year to conceive) have a higher rate of birth defects. It is also possible that the laboratory handling of eggs and sperm and embryos somehow damages them and thus increases the risk of birth defects. However, one study that looked at a group of IVF kids with birth defects could not find evidence that the IVF lab procedures were the cause. And it may be that closer scrutiny of children born by means of all assisted reproduction results in a higher reported rate of birth defects, thus misleadingly boosting the apparent relative risk.

Based on this study, Caplan asserts, "We need to be sure that long-term monitoring of children born by means of infertility treatment is routine and that more research is done into the causes of health problems for kids who cannot make choices about facing risk."

First, as far as I can tell, most studies that have monitored IVF kids are reassuring. For example, a 2010 follow up study of IVF kids up to grade 12 reported, "IVF children scored higher on standardized tests than their matched peers, suggesting that IVF does not have a negative effect on cognitive development." (One earlier study had suggested that children conceived using IVF were taller than spontaneously conceived children, but a subsequent study found no such difference.)

Look, if these data stand up, then of course people who are considering using IVF should be told about the increased risks to their potential children. But how likely is it that parents would decide not to risk having a kid because there is a three percent chance they would suffer from a significant birth defect? That's the normal risk that any parent and any would-be kid face now. So raise the chance to four percent. How many people would change their minds about having a kid because of that increased risk? I suspect not too many.

Consequently, I am not quite sure what to make of Caplan's ominous assertion that seems to suggest that the risks faced by kids born via assisted reproduction are somehow more ethically significant than the risks faced by children born by conventional means.

Nobody gets to choose who their parents are or what their characteristics will be before birth. Assisted and spontaneously conceived kids stand in exactly the same ethical relation to their parents with regard to the risks of being born.~Downtown Charlottesville denizen Ronald Bailey is the science correspondent for nationally-circulated Reason magazine (where this essay first appeared) and the author of "Liberation Biology: A Moral and Scientific Defense of the Biotech Revolution."

8 comments

NancyDrew May 11th, 2012 | 7:49am

The risk of birth defects might hinder some prospective parents from going forward, but the greater health risk may be from the types of IVF being attempted. Most health insurance policies provide no coverage for these procedures and that seems to have unintended consequences as reported here :

" The rate of twins and triplets in the U.S. has soared 70 percent in recent decades, thanks in large part to new technologies to overcome infertility. But the rise in multiple births means more premature babies and health complications.
Now, a new study finds that providing insurance coverage for fertility treatments means fewer multiple births.

I have 2 beautiful healthy little girls thanks to IVF and FET. I think the results of this study are being reported in a way that is meant to scare people from doing fertility treatments. Did anyone consider that the reason a couple can't conceive on their own is the same reason their child via IVF, ICSI, etc. is born with a birth defect? Essentially these reproductive techniques are scientifically making something happen that can't and maybe shouldn't happen for a biological reason. There is no way to know whether or not the same child born naturally to the same couple would also be born with a birth defect. Just some food for thought!

Chris May 11th, 2012 | 10:45am

You really need to include some links to the research and other sources in this piece.

Sean May 14th, 2012 | 12:47pm

Our preterm birth rate has doubled since Roe vs. Wade. That is, a 100% increase. UVA, VCU, and Planned Parenthood continue to deliberately keep women in the dark about abortion's effects on later pregnancies. The partisan media gives them a free pass.

Sean, there haven't been enough abortions performed in this country to cause anything like that level of increase in preterm birth rate. Even if every woman who had an abortion went on to have another pregnancy and that pregnancy was preterm.

Sean May 14th, 2012 | 7:21pm

Chris, you clearly have no idea - none whatsoever - that the number is over 54 MILLION in the US alone. Probably much higher given the dishonesty from providers. If it were 1/10 that, it would still be more than enough to account for countless thousands of needless cases of cerebral palsy and other developmental disabilities. Science > Politics.

Sean May 14th, 2012 | 8:13pm

These medical facts, citations, and settled science have been posted on this website several times previously - and usually deleted. The staff at the Hook are AOK with a 100% increase in preterm birth, so they of all people posting an article about a 37% increase is pretty silly. They are also AOK with women continuing to be ill informed about major causes of it also. Especially right here at UVA. They will NEVER mention it. Kids with cerebral palsy born to UVA grads are AOK with them, so long as their political agenda stays steady.

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